Method for controlling a textile machine,particularly an automatic cross-winding machine,as a function of yarn travel,and apparatus for carrying out the aforesaid method



Aug. 4, 1970 H. WERFFELI 3,522,913

METHOD FOR CONTROLLING A TEXTILE MACHINE, PARTICULARLY AN AUTOMATICCROSS-WINDING MACHINE, As A FUNCTION OF YARN TRAVEL, AND APPARATUS FORCARRYING OUT THE AFORESAID METHOD Filed Sept. 17, 1968 2 Sheets-Sheet 1INVENTOR #AM4w WFFAZ/ BY 1M ATTORNEYS.

H. WERFFELI 3,522,913

PARTICULARLY AN AS A FUNCTION OF AND APPARATUS FOR CARRYING OUT THEAFORESAID METHOD Aug. 4, 1970 METHOD FOR CONTROLLING A TEXTILE MACHINE.

AUTOMATIC CROSS-WINDING MACHINE,

YARN TRAVEL,

2 Sheets-Sheet 2 Filed Sept 17. 1968 Fig. 4

INVENTOR Maui/w) hitefifzu By W t t Fig. 3

ATTORNEY5 United States Patent 01 3,522,913 METHOD FOR CONTROLLING ATEXTILE MA- CHINE, PARTICULARLY AN AUTOMATIC CROSS-WINDING MACHINE, AS AFUNCTION OF YARN TRAVEL, AND APPARATUS FOR CARRYlNG OUT THE AFORESAIDMETHOD Hermann Werfieli, Horgen, Switzerland, assignor toMaschinenfabrik Schweiter AG, Horgen, Switzerland, a corporation ofSwitzerland Filed Sept. 17, 1968, Ser. No. 760,318 Claims priority,application Switzerland, Sept. 26, 1967, 13,405/ 67 Int. Cl. B65h 63/00US. Cl. 242-36 Claims ABSTRACT OF THE DISCLOSURE A method and apparatusfor controlling a textile machine such as an automatic cross-windingmachine, in dependence upon the path of travel of the yarn is disclosed.Electrical signals are produced as the yarn travels through the machine,a positive voltage peak indicating a section of enlarged yarn thickness,a negative voltage peak indicating the falling out of the yarn from itspath of travel. The positive voltage peak is subsequently utilized fortriggering a yarn cleaning or cutting mechanism and the negative voltagepeak is subsequently utilized for triggering a bobbin exchangeoperation. However, when a yarn cutting or cleaning operation is beingeffected, the yarn necessarily would have fallen out of its path oftravel, i.e. a negative voltage peak will have been generated inresponse thereto. Since, in this instance, a bobbin exchange operationis not desired, the subject invention provides means for suppressing orinhibiting the effect of the negative voltage peak produced during theyarn cutting or cleaning operation. Thus, in a simple, electronicfashion, the cleaning and bobbin exchange operations, necessary intextile machines, are accomplished.

BACKGROUND OF THE INVENTION The present invention relates to an improvedmethod of and apparatus for controlling a textile machine, in particularan automatic cross-winding machine, as a function of the movement ortravel of the yarn.

As is generally known, and as occurs in automatic winding machineshaving a plurality of winding stations or locations, the yarn at eachwinding location is under constant supervision so as to trigger anautomatic yarn servicing mechanism, such as an automatic bobbin exchangemechanism and/or an automatic yarn knotting mechanism and the likewhenever yarn defects occur, to thus remedy the defect at the particularaffected winding location. In order to accomplish this purpose,so-called yarn cleaners are, on the one hand, operably associated withthe yarn paths of travel and, on the other hand, drop brackets orlambellae feelers or the like are provided as monitoring elements. Inthis regard, the so-called yarn cleaners are capable of placing anautomatic yarn knotting mechanism into operation in response to yarndefects, whereas the drop brackets or lambellae are utilized to triggeran automatic delivery bobbin exchange mechanism. It has been found,however, that drop brackets, lambellae feelers, and similar monitoringelements of mechanical configuration no longer meet modern requirementsresulting from the continually increasing yarns speeds in use, in thatsuch drop brackets, or feelers bear upon the yarn and load the same inan undesirable fashion, and furthermore, the increased inertia upon suchmechanical configurations caused by continuous deposits of dirt and dustgreatly inhibits an instantaneous or immediate response of the element.

In contrast with the disadvantages of the mechanical drop brackets,lambellae feelers and the like, yarn cleaners have proven to beinertia-free and maintenance free yarn monitoring elements which do notadversely affect the yarn itself. In this regard, yarn cleaners monitoror supervise the yarn within the operating region of an auto matic yarnknotting mechanism whereby the yarn pro duces an electrical signal atthe path of travel thereof as defined or limited by a capacitive orphotoelectric cell. The electrical signal normally is an AC. signalgenerated by virtue of fluctuations in the yarn diameter which aresubsequently amplified and rectified, the resultant DC. signal thusobtained being evaluated as an indication of the presence of yarn movingin the prescribed path of travel. If the yarn is stopped or if the yarnis entirely absent at such prescribed path of travel, the DC. signalwill thus be removed. In consequence thereto, the relevant Windinglocation is placed out of operation, preferably via relay arrangementsor the like and the automatic yarn knotting mechanism is then actuated.On the other hand, if the yarn passing through the prescribed path oftravel exhibits an impermissible enlarged or thickened location, then aso-called positive voltage peak results on the electrical signal, thispositive voltage peak being utilized for triggering a yarn cutting orcleaning operation and, subsequent thereto, the winding location is madetemporarily inoperative and the knotting operation initiated due to theabsence of the above-described DC. signal. A yarn cleaner control asgenerally described above, for example, is known in the art and isdepicted in detail in the commonly assigned Swiss Pat. No. 389,470.

Accordingly, the above-described yarn cleaner as utilized with theconventional variety of control techniques serves to control the textilemachine as a function of the yarn condition only so long as the yarnremains in the effective or operable zone of the automatic knottingmechanism and can be seized by such knotting mechanism. On the otherhand, with such conventional control techniques, if the yarn rupturesoutside of this effective or operable zone or if the delivery bobbinbecomes depleted, then a mechanical scanner or feeler is placed intooperation and initially triggers operation of the automatic deliverybobbin-exchange mechanism.

SUMMARY OF THE INVENTION Accordingly, a primary object of the presentinvention relates to an improved method of and apparatus for controllingan automatic cross-winder as a function of yarn travel which serves toovercome the aforementioned drawbacks of prior-art techniques andstructures.

Another significant object of the subject invention relates to animproved method of and apparatus for controlling an automaticcross-winder or the like as a function of yarn travel by employing onlya yarn cleaner as the single yarn monitoring element thus eliminatingthe use of brackets, feelers or the like and thus eliminating thedisadvantages previously described with respect to such mechanicalconfigurations.

Still a further significant object of the present invention resides inthe provision of an improved technique and apparatus for supervisingyarn travel at a textile machine such as an automatic cross-winder, in amanner which not only is less likely to damage the yarn by avoiding theuse of certain prior-art elements such as mechanical feelers or the likewhich physically contact the yarn and which were previously thought tobe necessary for yarn supervisory functions, but also results in a lesscomplicated apparatus structure which is not as subject to malfunctionand which requires far less maintenance than was the case with theprior-art.

The above-defined objects as well as others which will become apparentare implemented by the subject invention in that the method thereof ischaracterized by the fea-- tures that the amplified signal at the outputside of the yarn cleaner or measuring cell, in addition to beingutilized for triggering a yarn cleaning and knotting operation, also isutilized for actuating the automatic delivery bobbin exchange mechanismand, in so doing, avoids the disadvantages of the bracket-type monitoror feeler or other mechanical devices for this purpose as discussedabove. In this respect, a negative voltage peak which occurs on theelectrical signal produced by yarn travel represents the falling of theyarn out of its normal path of travel and that this negative voltage isevaluated and utilized, after a threshold value is surpassed, forbringing in a new yarn, i.e. for triggering the automatic deliverybobbin exchange operation. Furthermore, a positive voltage peakappearing on the electrical signal caused by yarn passage whichrepresents an impermissible enlargement or thickness in the yarn andwhich is normally utilized for triggering a yarn cleaning or cuttingoperation is utilized also, in accordance with the subject invention,for inhibiting or suppressing the effect of the negative voltage peaksignal which causes the new yarn to be brought in. Thus, an automaticdelivery bobbin exchange operation is prevented from taking place duringperiods of operation of the yarn cutter or cleaner.

For purposes of clarity, a positive voltage peak is to be understood tobe that voltage produced during the path of travel of the yarn when thediameter of the traversing yarn changes in excess of a predeterminedvalue.

The novel inventive method proceeds from the fact that when the yarnfalls out of the measuring zone, a voltage peak also appears prior tothe signal falling to a zero or rest level which likewise is indicativeof no yarn movement, this voltage peak occurring in a direction oppositeto the direction of the voltage peak caused as a result of enlarged yarnthickness. This signal change described as a negative voltage peak inaccordance with the above definition not only appears when the yarnsupply is exhausted and wherein a new yarn must subsequently be broughtin, but also appears or occurs when the yarn is cut because of an areaof enlarged thickness. In this latter instance, it will be appreciatedthat an automatic delivery bobbin exchange operation is not necessarysince the yarn only needs to be re-knotted. Therefore, a feedbackcoupling of the signal resulting from the positive voltage peak isutilized so as to prevent the automatic delivery bobbin exchangeoperation during such periods.

By virtue of these inventive measures and techniques, it is now possibleto effect control of a textile machine in dependency upon the path oftravel of the yarn and through the use of a single supervisorymonitoring member, that is, a yarn cleaner, the result being asubstantially simpler and far safer and faster operation of the textilemachine.

The subject invention further relates to a novel, improved apparatus forcarrying out the aforesaid method, the novel apparatus having anelectric feeler or sensing means, the output of which is, on the onehand, coupled with a first circuit means responsive to certain voltageconditions so as to effect a yarn cleaning or cutting operation. On theother hand, the output of the electric feeler or sensing means isfurther coupled with a second circuit means responsive to certainvoltage conditions for stopping or turning ofi the relevant windinglocation. The output of the electric feeler or sensing means isconnected with an additional evaluation circuit, preferably anintegrator circuit, with which a further switch means is associated, thefurther switch means responding to certain voltage conditions fortriggering the automatic delivery bobbin exchange mechanism. A switchingelement is disposed in the circuit of the delivery bobbin exchangemechanism switch means, the switch element, when actuated, inhibitingoperation of the delivery bobbin exchange mechanism. This switch elementis itse f contemplated to be actuated by the output circuit of the yarnmonitoring, feeling or sensing means.

BRIEF DESCRIPTION OF THE DRAWINGS Additional advantages and features ofthe invention will become apparent when consideration is given thefollowing detailed description of preferred inventive embodiments, suchdescription making reference to the appended drawings wherein:

FIG. 1 depicts a schematic representation of a winding location of anautomatic winding machine;

FIG. 2 depicts a circuit arrangement of a yarn cleaner having anevaluation circuit;

FIG. 3 is a schematic diagram of the voltage variation occurring at theoutput of the measuring cell of a yarn cleaner under various operationalconditions and as a function of the measuring time;

FIG. 4 is an electrical circuit schematic of a control switch operableby the evaluation circuit of FIG. 2;

FIGS. 5 and 6 depict two embodiments of measuring slots found at theyarn cleaner.

DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS Referring now to FIG. 1, awinding location 10 is depicted, a plurality of these locations beingmounted on a rotating table of an automatic winding machine not depictedin detail in the drawings. A so-called automatic yarn knotting mechanismas well as an automatic delivery bobbin exchange mechanism are disposed,in known fashion, outside the rotary path of the winding locations 10.Each of the winding locations can be brought into operational contactwith the automatic knotting mechanism and the automatic delivery bobbinexchange in known fashion. Details of a machine of the type-describedare not necessary for an understanding of the subject invention, thesedetails being well-known in the art.

A yarn P is drawn off a delivery bobbin 11 at winding location 10 and isdelivered to a wind-up or take-up bobbin 17 via a balloon breaker 12, abrake 13, an electronic yarn cleaner 14, a deflecting plate 15, and agrooved drum 16. The directional movement which the yarn takes ismonitored by the yarn cleaner 14 which, in dependence upon theoperational condition thereof, brings winding location 10 intooperational contact or association with an automatic yarn knottingmechanism and the automatic delivery bobbin exchange mechanism andfurther serves to trigger the action of one or the other mechanisms asis described below in greater detail.

For example, the automatic yarn knotting mechanism must be initiatedinto action when the yarn is ruptured in a location between the brake 13or the yarn cleaner 14, respectively, and the winding bobbin 17 or,alternatively, if the yarn is separated or cut by the yarn cleaner 14.In both instances, the automatic yarn knotting mechanism serves to takeup both ends of the yarn and knot them together such that operation ofthe automatic delivery bobbin exchange mechanism is prevented and theexchange of the delivery bobbin 11 itself is avoided. On the other hand,if the yarn is ruptured below the brake 13 or if the delivery bobbin 11is depleted or empty, then prior to knotting the yarn ends together, thedelivery bobbin 11 must necessarily be replaced.

FIG. 2 depicts a circuit arrangement of a yarn cleaner generallydesignated 14 having a suitable evaluation circuit for evaluating theoccurrence of the above-mentioned disturbances and for triggering theproper disturbanceeliminating mechanism. In accordance with therepresentation of FIG. 2, the yarn cleaner 14 is seen to comprise aphotoelectric measuring cell 18 the output of which is coupled to anamplifier 19. Amplifier 19, amongst other functions, provides a signalto a relay 21 via a threshold value circuit arrangement 20, the relay 21being operable to actuate a yarn cutting knife 22.

A first evaluation circuit generally depicted by reference numeral 23 iscoupled to the output of amplifier 19 and serves to turn off or disablethe Winding location of FIG. 1. Evaluation circuit 23 is seen tocomprise an amplifier 24, a rectifier 25 and a control relay 26.

As mentioned above, yarn F produces an alternating current signal in theoutput of the measuring cell 18 as the yarn passes measuring cell 18 byvirtue of diameter variations of the yarn. The alternating current has awave form as depicted by curve 27 of FIG. 3. The alternating current isamplified by amplifier 24 and is then rectified by rectifier 25 of theevaluation circuit 23. The output signal from rectifier 25 is normally acontinuous signal which is then applied to the control relay 26.However, when the travelling yarn exhibits a point of enlarged thicknessor diameter in the area of measuring cell 18, a positive voltage peak asdepicted in curve 28 of FIG. 3 is produced at the output of measuringcell 18. When the yarn falls out of its normal path of travel, anegative voltage peak as depicted by curve 29 of FIG. 3 is produced bythe measuring cell. Finally, in the situation wherein the yarn ismissing or wherein the yarn is not moving, a zero voltage is illustratedby curve 30 of FIG. 3 is produced by the measuring cell 18. As a resultof either the negative voltage peak 29 or of the zero voltage condition30, the direct current signal at the output of rectifier 25 will beremoved and thus result in a switching operation of the control relay 26which serves to actuate the turn-off of the afiected winding locationand further serves to initiate operation of the automatic knottingmechanism unless a signal is present, as will be discussed below, whichgives preference to the actuation of the automatic delivery bobbinexchange operation instead.

If an enlarged thickness at the yarn occurs, the output signal fromamplifier 19 will change and will take the form of the voltage impulseor positive voltage peak 28 as depicted in FIG. 3. If this voltage peaksurpasses a particular predetermined threshold value of the thresholdswitch 20, then the relay 21 is immediately excited and triggers thecutting of the yarn by knife 22. Reference is made to curve 21' of FIG.3 wherein the switching time of relay 21 is depicted.

As mentioned above, a voltage peak as illustrated in curve 29 of FIG. 3,that is a negative voltage peak, represents the falling of yarn F out ofits normal path of travel through the measuring cell 18. The negativevoltage peak of curve 29 serves the purpose of producing a signal whichcan be utilized for bringing in a new yarn, that is for triggeringoperation of the automatic delivery bobbin exchange mechanism. For thispurpose, a second evaluation circuit generally designated by referencenumeral 31 is provided, the second evaluation circuit 31 comprising twoinputs 32 and 33, respectively. One input 32 is connected in parallelwith the output of amplifier 19 of a yarn cleaner 14 and is furtherconnected with a first input 132 of an electronic gate or switchingmeans 34. The other input 33 of the second evaluation circuit 31 isconnected in parallel to the output side of the rectifier 24 of thefirst evaluation circuit 23 and is further connected to a second input133 of the electronic gate 34 via parallely connected timing circuits tand t and a further gate or switch circuit 35 serially connected withthe timing uircuits t and t An integrator 36 and a threshold valueswitch means 37 having a relay 38 associated with the output thereof areconnected to the output of gate 34.

If the yarn F falls out of the zone of the measuring cell 18 due to arupture occurring below the brake 13 of FIG. 1 or because of a depletionor emptying of the delivery bobbin 11, then a signal represented bycurve 29 of FIG. 3 would appear at the input 132 of the gate 34. Inorder to open gate 34, however, a signal at input 133 must also appear.This signal will appear, however, only if timing circuit i generates asignal to gate 35. On the other hand, if a direct current signal ispresent at the inputs of timing circuits t and t then gate 35 isblocked. Since, however, the direct current signal is removed in thepresence of the negative voltage peak 29, the result is that the timingcircuits t and t are switched in a manner such that first t and then ttemporarily suppress the input signal to gate 35, this operation beingachieved, for example, by means of delayed-release relays. In thismanner, gate 34 becomes conductive only in the period of time t -t inaccordance with FIG. 3, this action overcoming the deleterious effect ofany spurious disturbances in the system. Now, if the output signal fromintegrator 36 surpasses the particular predetermined threshold value ofthe theshold switch 37, relay 38 will respond and, via contact 38, wouldinitiate the operation of the automatic delivery bobbin exchangemechanism. If, however, the yarn F is ruptured in such a manner that theyarn remains within the measuring zone, gate 34 would still receive asignal via the inputs 132 and 133 and thus become conductive. Duringthis operation, however, the zero signal level 30 reaches the integrator36 via the input 132. As a result thereof, integrator 36 cannot producean output signal which surpasses the particular threshold value of theswitch 37 so that relay 38 cannot respond. Curve 38" of FIG. 3 depictsthe switching time of relay 38.

As previously explained, the yarn F may fall out of the measuring zoneunder some conditions without making a delivery bobbin exchangeoperation desirable. This condition occurs if the yarn F is cut throughby the yarn cleaner 14 in the above-described manner upon the appearanceof an undesired point or area of thickness or enlargement in thediameter thereof. In such case, the yarn separation signal is usedadditionally for suppressing the signal serving to actuate the automaticdelivery bobbin exchange mechanism. For this purpose, a timing circuit tis provided in parallel circuit arrangement to the relay 21 of thecutting knife 22 of yarn cleaner 14, the timing circuit opening a switch2" in response to the yarn separation signal at time t pursuant to covert" of FIG. 3. Time t;; as utilized herein suitably corresponds to thedamping time of the negative voltage peak 29 until the occurrence of theresting or no-signal potential voltage 30.

The switch t is disposed in a control circuit as depicted in FIG. 4,switch t being in series with a switch-on relay mechanism 40 for controlof the automatic delivery bobbin exchange mechanism and further isdisposed in series with a switching contact 38' of relay 38 whichactuates the exchange operation.

Now, if the yarn F falls outside of the zone of the measuring cell orsensing means 18 as a result of the cutting or separation thereof by theyarn cleaner 14 actuated by an impulse at the cutting relay 21, aninitiating signal for the automatic delivery bobbin exchange mechanismis still given via contact 38 of relay 38. But, in this instance theinitiating signal is inhibited or suppressed through the operation ofcontact 1 of the timing circuit t together with the separation signalsince timing contact t opens as can easily be determined by FIG. 4.

It should be mentioned at this point that the scope of the invention isnot limited to the switching arrangement as specifically describedabove. Thus, widely varying switching elements may be thought of astiming circuits t, t, and t or the feedback coupling of the signal fromthe outlet of the yarn cleaner to the evaluation circuit for thenegative voltage peak may be effectuated without contacts in diiferentmanners.

It may be mentioned further that the yarn cleaner can suitably beprovided with a slot cover so as to prevent the yarn from jumping out ofthe measuring slot of the yarn cleaner inasmuch as the pre-tensionproduced as a result of the formerly used drop bracket type monitors orlamellae feelers is absent at the yarn in the subject inventivearrangement.

Pursuant to FIG. 5, this slot cover can be a slide member 50 at thefront end of the yarn cleaner 14, the slide member being kept in closedposition against the efiect of a spring 52 by an electromagnet 51. Theelectromagnet 51 is excited for the purpose of emplacing yarn F as aresult of which the closure position is opened.

According to FIG. 6, the slot cover is seen to comprise a flap member 53which may be tilted inwardly for the purpose of inserting yarn F intothe measuring slot of yarn cleaner 14.

It should be apparent that the objects set forth at the outset of thisspecification have now been successfully achieved accordingly, what isclaimed is:

What is claimed is:

1. In a method for controlling a textile machine such as an automaticcross-winding machine in dependency upon the traversing yarn wherein theyarn is monitored during its path of travel through the machine andwherein an A.C. electrical signal is produced representing diametervariations of the yarn, the A.C. signal being amplified and rectified,the resultant DC. signal being indicative of yarn presence, and whereina positive voltage peak of the electrical signal representative ofpoints of enlarged yarn thickness is utilized after surpassing athreshold value for cutting the yarn, the improvement which comprisesthe further steps of exchanging the yarn delivery bobbin in response toa negative voltage peak of the electrical signal after a threshold valuehas been exceeded, the negative voltage peak representing the falling ofthe yarn out of its normal path of travel; and inhibiting the deliverybobbin exchange operation in response to the presence of a priorpositive voltage peak which has initiated a yarn cutting operation.

2. The improvement as defined in claim 1 wherein the exchange operationis responsive to an integration of the negative voltage peak as afunction of time.

3. An apparatus for controlling a textile machine such as an automaticcross-winding machine in dependency upon the traversing yarn, saidapparatus comprising: electrical sensing means having an output formonitoring the yarn and for producing an electric signal in responsethereto; yarn cutting means for cutting the yarn; first cir cuit meanscoupled to said output of said electrical sensing means and responsiveto a first voltage condition, said first circuit means including aswitch member to actuate said yarn cutting means; second circuit meanscoupled to said output of said electrical sensing means and responsiveto a second voltage condition to render inoperable a given windinglocation; third circuit means coupled to said output of said electricalsensing means and responsive to a third voltage condition, said thirdcircuit means including a switch member for actuating a yarn deliverybobbin exchange operation; and switch means coupled with said first andthird circuit means for inhibiting actuation of the yarn delivery bobbinexchange operation upon actuation of said yarn cutting means.

4. Apparatus as defined in claim 3 wherein said switch member of saidthird circuit means includes a switching circuit for the actuation ofsaid yarn delivery bobbin exchange operation, and wherein said switchmeans coupled with said first and third circuit means includes a switchmember disposed in said switching circuit of said switch member of saidthird circuit means and responsive to operation of said switch member ofsaid first circuit means to inhibit operation of said switching circuit.

5. Apparatus as defined in claim 4, wherein said third circuit meansincludes an integrating circuit for integrating the voltage from saidoutput of said electrical sensing means as a function of time, andwherein said second circuit means includes a rectifier for rectifyingthe voltage from said output of said electrical sensing means.

6. Apparatus as defined in claim 5, further including a first gate meanshaving first and second inputs, and an output coupled with saidintegrating circuit, said first input "being coupled with said output ofsaid electrical sensing means, said second input being coupled with anoutput of said rectifier by coupling means.

7. Apparatus as defined in claim 6, wherein said coupling means betweensaid rectifier and said second input of said first gate means comprisesa time limiting circuit means.

'8. Apparatus as defined in claim 7, wherein said time limiting circuitmeans comprises a second gate means having first and second inputs, andan output coupled to said second input of said first gate means, twoparallel connected timing circuits coupled between said rectifier andsaid respective first and second inputs of said second gate means.

9. Apparatus as defined in claim 5, wherein said switch member of saidswitch means disposed in said switching circuit of said switch member ofsaid third circuit means and responsive to operation of said switchmember of said first circuit means comprises an electrical contact, saidswitch means comprising a further timing circuit means disposed parallelto said switch member of said first circuit means for operating saidelectrical contact.

10. Apparatus as defined in claim 9, wherein said switching circuit ofsaid switch member of said third circuit means comprises a seriescircuit connection of an electrical contact operated by a relay in theoutput of said third circuit means, said electrical contact of saidswitch means, and a switching relay for actuating said yarn deliverybobbin exchange operation.

References Cited UNITED STATES PATENTS JOHN PETRAKES, Primary Examiner

